Christopher's premiere solar design tool is SunAngle, a shareware program used around the world since 1995 to calculate solar angles based on location, date, and time. SunAngle runs directly in your web browser.

A more sophisticated version of SunAngle is also available for purchase. The SunAngle Professional Suite includes additional features, thorough technical documentation, and full technical support. It's available for sale on CD-ROM or by e-mail delivery.